Which of the following does NOT contain aluminum as a component?

Container for trioxonitrate (v) acid

Which of the following roles does sodium chloride play in preparation? It

purifies the soap, accelerates the decomposition of fat and oil

converts the fat acid to its sodium salt

JAMB UTME - Chemistry - 2022 | Green Bridge CBT

Question 1 Report

The removal of rust from iron by treatment with tetraoxosulphate (vi) acid is based on the

Hydrolysis of the iron

Reaction of acid with base

Oxidation of the rust

Dehydration of the iron

Answer Details

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 2 Report

What volume of (dm\(^{3}\)) of water will be added to 10dm\(^{3}\) of 2.0 mol/dm\(^{3}\) HCL acid solution to give a final solution of 0.5 mol/dm\(^{3}\)?

Answer Details

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Question 3 Report

Which of the following statement is TRUE of the complete hydrolysis of a glyceride by sodium hydroxide?

3 moles of NaOH are required for each mole of glyceride

3 moles of glycerol are produced

only one mole of soap is formed

concentrated H2SO4 is essential for the completion of the reaction.

Answer Details

The statement that is TRUE of the complete hydrolysis of a glyceride by sodium hydroxide is: - 3 moles of NaOH are required for each mole of glyceride. During the hydrolysis of a glyceride (a triglyceride), the ester bonds between the fatty acid chains and glycerol are broken by the action of a strong base like sodium hydroxide. This results in the formation of glycerol and the corresponding salts of fatty acids, which are commonly known as "soaps." The reaction can be represented by the following equation: Triglyceride + 3 NaOH → 3 soap + glycerol As per the equation, 3 moles of NaOH are required to hydrolyze one mole of glyceride, and 3 moles of soap and one mole of glycerol are produced. The use of concentrated sulfuric acid (H2SO4) is not essential for the completion of the reaction, but it can be used as a catalyst to speed up the reaction.

Read lesson note on Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

Chemistry Of Carbon Compounds (Nigeria Only)

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Question 4 Report

Ethene, when passed into concentrated H2SO4, is rapidly absorbed. The product is diluted with water and then warmed to produce

Ethanol

diethyl ether

ethanal

diethyl sulphate

Answer Details

When ethene is passed into concentrated H2SO4, it undergoes electrophilic addition reaction to form ethyl hydrogen sulfate as the product. The reaction mixture is then diluted with water and warmed to produce ethanol as the main product. Therefore, the answer is ethanol.

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Question 5 Report

A piece of radioactive element has initially 8.0×10^22 atoms. The half life of two days after 16 days the number of atom is

5×10^21

5×10^22

25×10^21

25×10^22

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 6 Report

A certain liquid has a high boiling point. It is viscous, non-toxic, and miscible with water to be hygroscopic; this liquid most likely to be

CH3CH2CH2CH2OH

CH3CH2CHOH3

CH3CH2CH2CH2OH3

CH3OHCHOH2OH

Answer Details

The liquid is most likely to be option number 4: CH3OHCHOH2OH, which is also known as glycerol or glycerin. Glycerol has a high boiling point of 290°C, which is much higher than the boiling points of the other options. It is also a viscous liquid, which means it is thick and sticky. Glycerol is non-toxic, and it is often used in food, pharmaceuticals, and cosmetics. Furthermore, glycerol is miscible with water, which means that it can be easily mixed with water to form a homogeneous solution. It is also hygroscopic, which means that it can absorb water from the air. These properties make glycerol a useful substance in many applications, such as as a moisturizer in skincare products or as a humectant in food processing.

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 7 Report

An organic compound which liberate carbon(iv)oxide from trioxocarbonate(iv) solution is likely to be?

_{2}

_{5}

_{3}

_{4}

_{6}

_{6}

_{3}

COOH

Answer Details

The organic compound that liberates carbon(iv)oxide from trioxocarbonate(iv) solution is CH3COOH (acetic acid). When acetic acid is added to a solution of trioxocarbonate(iv) (carbonate) it reacts to form carbon(iv)oxide gas, water and a salt. The balanced chemical equation for the reaction is: 2CH3COOH + Na2CO3 → CO2 + 2H2O + 2NaCH3COO The carbon(iv)oxide gas is released as bubbles, causing the solution to fizz. Therefore, CH3COOH is the organic compound that liberates carbon(iv)oxide from trioxocarbonate(iv) solution.

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Question 8 Report

Hard water is water with high concentrations of dissolved ions, in particular calcium and

magnesium ions

nitrogen ions

phosporus ions

helium ions

Answer Details

Hard water is water that contains high amounts of dissolved minerals, specifically calcium and magnesium ions. These minerals come from the rocks and soil that the water flows through and can accumulate in the water as it travels to your home. When you use hard water, it can leave mineral deposits on your pipes, fixtures, and appliances, which can reduce their efficiency and lifespan. It can also make soap less effective and leave your skin feeling dry and itchy. Therefore, it is important to treat hard water if it is a problem in your area.

Read lesson note on Solubility Of Substances (Ghana Only) (WAEC)

Solubility Of Substances (Ghana Only)

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Question 9 Report

Which of the following is stable to heat

NaHCO3

( NH4 )2 SO4

Ag NH3

K2 CO3

Answer Details

Out of the given options, K2CO3 is stable to heat.

Read lesson note on Non-metals And Their Compounds (JAMB)

Non-metals And Their Compounds

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Question 10 Report

There is a large temperature interval between the melting point and the boiling point of metal because:

metals have a very high melting point

metals conduct heat very rapidly

melting does not break the metallic bond but boiling does

the crystal lattice of metal is easily broken

Answer Details

The correct answer is: "melting does not break the metallic bond but boiling does." The metallic bond is the force of attraction between metal atoms, which holds them together to form a solid. When a metal is heated, its temperature increases, and at a certain point, the energy provided by the heat is enough to overcome the metallic bond and cause the metal to melt. However, even in the liquid state, the metallic bond remains intact, which is why metals have a very high melting point. On the other hand, when the temperature is further increased, the energy provided by the heat becomes enough to break the metallic bond, and the metal atoms become completely detached from one another. This results in the metal boiling and turning into a gas. Because the metallic bond is much stronger than other types of intermolecular forces, such as van der Waals forces, it requires a lot of energy to break, resulting in a large temperature interval between the melting point and boiling point of metal.

Read lesson note on Water (JAMB)

Read lesson note on Structure Of The Atom (WAEC)

Water

Structure Of The Atom

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Question 11 Report

\(\mathrm{N_2O_4}\) ? \(2\mathrm{NO_2}\) (? = -ve)

From the reaction above, which of these conditions would produce the highest equilibrium yield for \(\mathrm{N_2O_4}\)?

Low temperature and high pressure

Low temperature and low pressure

high temperature and low pressure

high temperature and high pressure

Answer Details

The highest equilibrium yield of N2O4 would be produced at low temperature and low pressure. In a chemical reaction, the position of the equilibrium can be influenced by changing the temperature or pressure. A decrease in temperature or an increase in pressure favors the side of the reaction with the fewer moles of gas (in this case, N2O4). This means that, if the temperature is low and the pressure is low, there will be more N2O4 at equilibrium, as the reaction will shift to the right to counteract the reduction in the concentration of N2O4. So, low temperature and low pressure would produce the highest equilibrium yield of N2O4.

Read lesson note on Chemical Combination (JAMB)

Chemical Combination

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Question 12 Report

6g of Mg was to 100cm3 of 1 moldm3 H2 SO4 . What mass of Mg remained undissolved? (Mg = 24)

0.24g

2.4g

3.6g

0.36g

Answer Details

The balanced chemical equation for the reaction between magnesium (Mg) and sulfuric acid (H2SO4) is: Mg + H2SO4 -> MgSO4 + H2 According to the equation, one mole of Mg reacts with one mole of H2SO4 to produce one mole of magnesium sulfate (MgSO4) and one mole of hydrogen gas (H2). Since the concentration of the sulfuric acid is 1 moldm3, this means that there is one mole of H2SO4 in every 1 liter (1000 cm3) of solution. To determine the amount of Mg that reacts with the H2SO4, we need to use stoichiometry. One mole of Mg reacts with one mole of H2SO4, so the amount of Mg that reacts with 1 moldm3 of H2SO4 is given by: 6g / 24g/mol = 0.25 mol Since the reaction is 1:1, this means that 0.25 mol of H2SO4 is consumed in the reaction. The volume of the solution is 100cm3 (0.1 dm3), so the amount of H2SO4 in the solution is: 1 mol/dm3 x 0.1 dm3 = 0.1 mol The amount of H2SO4 that remains after the reaction is: 0.1 mol - 0.25 mol = -0.15 mol This negative value means that all of the H2SO4 was consumed in the reaction, and there is excess Mg left over. The mass of Mg that remains undissolved is given by: 0.15 mol x 24g/mol = 3.6g Therefore, the correct answer is 3.6g.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 13 Report

\(H^+ + OH^- \rightarrow H_2O\)

The equation above illustrates

precipitation

hydration

hydrolysis

neutralization

Answer Details

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

Acids, Bases And Salts (Ghana Only)

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Question 14 Report

In order to electroplate spoon with silver, the arrangement of the electrolytic cell is?

the anode is a silver rod and the cathode is the spoon

the anode is the spoon and the cathode is a silver rod

the electrolyte is silver trioxonitrate(v)( solution and the cathode is a silver rod.

the electrolyte is silver trioxonitrate(v) solution and the anode is the spoon

Answer Details

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Question 15 Report

A sample of gas with an initial volume of 2.5 dm3 is heated and then allowed to expand to 7.5 dm3 at constant at pressure. What is the ratio of the final temperature of the initial absolute temperature?

3:1

1:3

2:5

5:2

Answer Details

According to Charles's Law, the ratio of the initial and final temperatures is equal to the ratio of the initial and final volumes at constant pressure. The ratio of the final volume to the initial volume is: Vf / Vi = 7.5 dm3 / 2.5 dm3 = 3 Therefore, the ratio of the final temperature to the initial temperature is also 3: Tf / Ti = Vf / Vi = 3 So the answer is 3:1.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 16 Report

Which of the following increases as boiling water changes to steam?

Temperature of the system

degree of disorder of the system

number of molecule

Activation energy

Answer Details

The degree of disorder of the system increases as boiling water changes to steam. When water is boiled and changes to steam, the water molecules gain energy and become more disordered, which means that the molecules move more rapidly and the entropy of the system increases. The temperature of the system also increases during this process, but the degree of disorder is the factor that specifically increases as the water changes to steam. The number of molecules and activation energy remain constant during this phase transition.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 17 Report

What is the shape of a molecule of CCl4?

Pyramid

tetrahedral

Trigonal planar

linear

Answer Details

The shape of a molecule of CCl4 is tetrahedral.

Read lesson note on Atomic Structure And Bonding (JAMB)

Atomic Structure And Bonding

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Question 18 Report

An organic compound contains 69% carbon, 15.3% hydrogen and 30.7% oxygen. Calculate the the empirical formula [C=12, H = 1, O = 16]

_{4}

_{1} 2

_{3}

_{9}

_{4}

_{9}

_{3}

_{8}

Answer Details

View Answer

Question 19 Report

Chlorine is a common bleaching agent. This is not true with

wet litmus paper

printers ink

wet pawpaw leaf

most wet fabric dyes

Answer Details

Chlorine is not a common bleaching agent for wet litmus paper, wet pawpaw leaf, and most wet fabric dyes. It is commonly used as a bleaching agent for printer's ink.

Read lesson note on Acids, Bases And Salts (Ghana Only) (WAEC)

Acids, Bases And Salts (Ghana Only)

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Question 20 Report

Complete dehydrogenation of ethyne yields

benzene

methane

ethane

propane

Answer Details

Read lesson note on Chemistry Of Carbon Compounds (Nigeria Only) (WAEC)

Chemistry Of Carbon Compounds (Nigeria Only)

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Question 21 Report

H2SO4 is used to remove rust on the surface of iron (picking) before electroplating. The type of reaction involved is

redox reaction

Neutralization

Double decomposition

Hydrolysis

Answer Details

The type of reaction involved when using H2SO4 to remove rust on the surface of iron is a redox reaction. This is because the sulfuric acid oxidizes the iron in the rust, converting it into iron(II) sulfate, while the acid itself is reduced to sulfur dioxide. The overall reaction can be written as follows: Fe2O3(s) + 3H2SO4(aq) → Fe2(SO4)3(aq) + 3H2O(l) In this reaction, the iron in Fe2O3 is oxidized from a +3 to a +2 oxidation state, while the sulfur in H2SO4 is reduced from a +6 to a +4 oxidation state. This transfer of electrons between the reactants is what defines a redox reaction.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Read lesson note on Redox Reactions (WAEC)

Kinetic Theory Of Matter And Gas Laws

Redox Reactions

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Question 22 Report

Which of the following is used as a moderator to control nuclear fission?

Lead

Heavy water

Iron

Chromium

Answer Details

Heavy water (D2O) is used as a moderator to control nuclear fission. A moderator is a substance that is used to slow down the neutrons produced in a nuclear reaction, making them more likely to be captured by the fuel nuclei and causing further fission. Heavy water is a type of water that contains a larger amount of the isotope deuterium (D) than regular water. Deuterium has an extra neutron compared to the more common hydrogen isotope, and this makes heavy water more effective at slowing down neutrons than regular water. Lead, iron, and chromium are not typically used as moderators in nuclear reactors. Lead can be used as a shield to absorb radiation, while iron and chromium are used in the construction of the reactor vessel and other components.

Read lesson note on Electrolysis (JAMB)

Electrolysis

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Question 23 Report

The sulphide that is commonly used in coating electric fluorescent tubes is?

iron(ii)Sulphide

tin(ii)sulphide

Zinc Sulphide

lead(iv) Sulphide

Answer Details

The sulphide commonly used in coating electric fluorescent tubes is Zinc Sulphide. Zinc Sulphide is a type of material that glows when it is exposed to ultraviolet light. When ultraviolet light is generated inside a fluorescent tube, it excites the Zinc Sulphide particles, causing them to emit visible light. This visible light is what we see as the bright light coming from the tube. So, Zinc Sulphide acts as a phosphor and helps in producing the bright light in fluorescent tubes.

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 24 Report

Addition of charcoal to the filter bed of sand during water treatment for township supply is to?

prevent goiter

prevent tooth decay

remove odour

kill germs

Answer Details

The addition of charcoal to the filter bed of sand during water treatment for township supply is to remove odors and improve the taste of the water. Charcoal is a porous material that can adsorb impurities and chemicals from the water, such as dissolved organic matter that can contribute to unpleasant tastes and odors. This process helps to produce a better-quality drinking water that is free from unpleasant tastes and odors. It should be noted that while the addition of charcoal can help remove impurities, it does not kill germs or prevent tooth decay or goiter. Other water treatment methods, such as disinfection with chlorine or ultraviolet light, are required to kill harmful microorganisms and ensure the safety of the drinking water.

Read lesson note on Solubility (JAMB)

Solubility

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Question 25 Report

\( \mathrm{SO_2 + O_2 \rightarrow 2SO_3} \)

In the reaction above, the most suitable catalyst is?

chromium(vi)oxide

iron(iii)oxide

copper(i)oxide

vanadium(v)oxide

Answer Details

The most suitable catalyst for the given reaction is vanadium(V)oxide (V2O5). Vanadium(V)oxide is a commonly used catalyst for the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3). The reaction is an exothermic reaction, and it occurs at high temperatures (around 450-500°C) in the presence of a catalyst. V2O5 is an effective catalyst for this reaction because it has a high surface area and can provide active sites for the reaction to occur. The vanadium ions in the V2O5 catalyst undergo redox reactions with the sulfur dioxide and oxygen molecules, which promotes the formation of sulfur trioxide. Chromium(VI)oxide and iron(III)oxide are not suitable catalysts for this reaction because they are not effective at promoting the oxidation of sulfur dioxide to sulfur trioxide. Copper(I)oxide can be used as a catalyst for the reaction, but it is not as effective as vanadium(V)oxide.

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Question 26 Report

The boiling point of water, ethanol, toulene and butan-2-ol are 373.0k, 351.3k, 383.6k and 372.5k respectively, which liquid has the highest vapour pressure at 323.0k

water

toluene

ethanol

butan-2-ol

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 27 Report

Electrons enter into orbitals in order of increasing energy as exemplified by?

^{2}

^{2}

2PX

^{2}

2py

^{2}

2pz

^{0}

^{0}

^{2}

^{2}

2PX

^{2}

2py

^{1}

2pz

^{1}

^{0}

^{2}

^{2}

2PX

^{1}

2py

^{1}

2pz

^{1}

^{1}

^{2}

^{2}

2PX

^{2}

2py

^{2}

2pz

^{0}

^{1}

Answer Details

Read lesson note on Atomic Structure And Bonding (JAMB)

Atomic Structure And Bonding

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Question 28 Report

In the preparation of salts, the method employed will depend on the?

composition

dissociating ability

stability to heat

precipitating ability

Answer Details

The method employed in the preparation of salts will depend on the composition of the salt. Different salts have different chemical properties, and the method used to prepare them will depend on these properties. For example, some salts can be easily dissolved in water, while others are not very soluble and may require the use of a different solvent or special conditions to dissolve. The dissociating ability, stability to heat, and precipitating ability of the salt may also play a role in determining the preparation method, but the most important factor is the composition of the salt.

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 29 Report

GAS	\( \mathrm{CO_2} \)	\( \mathrm{N_2} \)	\( \mathrm{O_2} \)
% BY VOLUME	4	72	24

The above table shows the compositions of the atmosphere of planet X. Which of these gases are present in higher percentages on earth?

_{2}

and O

_{2}

_{2}

and CO

_{2}

_{2}

, O

_{2}

and N

_{2}

_{2}

and N

_{2}

Answer Details

Read lesson note on Separation Of Mixtures And Purification Of Chemical Substances (JAMB)

Separation Of Mixtures And Purification Of Chemical Substances

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Question 30 Report

Copper (II) tetraoxosulphate (IV) is widely used as

fertilizer

fungicide

Disinfectant

purifier

Answer Details

Copper (II) tetraoxosulphate (IV), also known as copper sulfate or CuSO4, is widely used as a fungicide and a disinfectant. As a fungicide, copper sulfate is effective in controlling fungal diseases in plants, including mildew, leaf spots, and blights. It is also used as a fungicide in swimming pools to prevent the growth of algae. As a disinfectant, copper sulfate is effective in killing bacteria and viruses. It is used in a variety of applications, including in the production of animal feed, as a preservative for wood, and in water treatment to kill bacteria and algae. While copper sulfate has been used as a fertilizer in the past, its use in this capacity has largely been replaced by other compounds. It is not commonly used as a purifier.

Read lesson note on Stoichiometry And Chemical Reactions (WAEC)

Read lesson note on Environmental Pollution (JAMB)

Read lesson note on Periodic Chemistry (Ghana Only) (WAEC)

Stoichiometry And Chemical Reactions

Environmental Pollution

Periodic Chemistry (Ghana Only)

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Question 31 Report

A colored gas that is known to be poisonous and can readily damage the mucous lining of the lungs is?

hydrogen sulphid

carbon(ii)oxide

chlorine

sulphur(iv)oxide

Answer Details

The colored gas that is known to be poisonous and can readily damage the mucous lining of the lungs is chlorine. Chlorine is a highly reactive chemical element that is used in the production of many everyday products, such as paper, textiles, and plastics. It is also used as a disinfectant in swimming pools and water treatment plants. Inhaling chlorine gas can cause severe respiratory problems, including coughing, chest pain, and difficulty breathing. Prolonged exposure to chlorine can cause lung damage, and in extreme cases, it can be fatal. Chlorine gas is also highly irritating to the eyes, skin, and mucous membranes. It is important to handle chlorine with caution and to use appropriate protective gear, such as gloves and respiratory masks, when working with it. Proper ventilation and monitoring of chlorine levels are also essential to prevent exposure to this toxic gas.

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Read lesson note on Organic Compounds (JAMB)

Kinetic Theory Of Matter And Gas Laws

Organic Compounds

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Question 32 Report

Using the metal activity series, the metal that can liberate hydrogen gas from steam is?

iron

copper

tin

lead

Answer Details

The metal that can liberate hydrogen gas from steam is iron. The metal activity series is a list of metals in order of their reactivity, with the most reactive metals at the top and the least reactive metals at the bottom. When a metal is placed in a solution of steam (water vapor), the metal will react with the steam if it is more reactive than hydrogen. In this case, iron is more reactive than hydrogen, so it can displace hydrogen from the steam to form hydrogen gas. This reaction can be represented by the equation: Fe + H2O (steam) → FeO (iron oxide) + H2 (hydrogen gas) So, when steam is passed over iron, hydrogen gas is liberated and iron oxide is formed.

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Question 33 Report

An organic compound with fishy smell is likely to have a general formula?

RCONHR

^{1}

RCONH

_{2}

RNH

_{2}

RCOR

^{1}

Answer Details

The organic compound with a fishy smell is most likely to have the general formula RNH2, which represents a primary amine. Amines are organic compounds that contain a nitrogen atom bonded to one or more carbon atoms. Primary amines have one alkyl or aryl group and two hydrogen atoms bonded to the nitrogen atom. Some primary amines have a fishy smell, which is caused by the presence of volatile amines. These amines are small molecules that can easily evaporate and have a strong odor, similar to that of fish. Examples of compounds that have a fishy smell include trimethylamine, which is found in fish, and butylamine, which is used in the production of rubber and pharmaceuticals. In summary, the organic compound with a fishy smell is likely to have the general formula RNH2, which represents a primary amine.

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Question 34 Report

A sample of gas exerts a pressure of 8.2 atm when confined in a 2.93 dm3 container at 20c. The number of moles of gas in the sample is

1. 00

2.00

3.00

4.00

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 35 Report

The function of sulphur during the vulcanization of rubber is to

act as a catalyst for the polymerization of rubber molecules

convert rubber from thermosetting to thermoplastic polymer

form chains which bind rubber molecules together

break down rubber polymer molecules

Answer Details

The function of sulphur during the vulcanization of rubber is to form chains which bind rubber molecules together.

Read lesson note on Rates Of Chemical Reaction (JAMB)

Read lesson note on Acids, Bases And Salts (JAMB)

Rates Of Chemical Reaction

Acids, Bases And Salts

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Question 36 Report

A quantity of air passed through a weighted amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of

nitrogen

neon

argon

oxygen

Answer Details

When air is passed through alkaline pyrogallol, the oxygen in the air is absorbed by the pyrogallol, resulting in an increase in the weight of the pyrogallol. The other gases in air, namely nitrogen, neon, and argon, do not react with pyrogallol under these conditions. Therefore, the answer is oxygen.

Read lesson note on Air (JAMB)

Air

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Question 37 Report

Which of the following will precipitate in dil. HCl

ZnS

Na2 S

Fe S

CuS

Answer Details

Among the given options, only CuS will precipitate in dilute HCl. CuS is insoluble in dilute HCl, and hence it will precipitate when added to dilute HCl. However, the other options will dissolve in dilute HCl, and hence they will not precipitate. ZnS will dissolve in dilute HCl to form ZnCl2 and H2S. Na2S will react with dilute HCl to produce H2S and NaCl. FeS will dissolve in dilute HCl to form FeCl2 and H2S. Therefore, the correct answer is (4) CuS.

Read lesson note on Acids, Bases And Salts (JAMB)

Acids, Bases And Salts

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Question 38 Report

The oxidation number of oxygen in BaO2 is

-2

-4

-1

Answer Details

To determine the oxidation number of oxygen in BaO2, we can use the fact that the overall charge of a compound must be zero. Barium (Ba) is a Group 2 element and has an oxidation state of +2. The compound BaO2 has no net charge, so the sum of the oxidation states of all the atoms must be zero. Let x be the oxidation state of oxygen in BaO2. Therefore, we have: (+2) + 2(x) = 0 Solving for x, we get: x = -1 Therefore, the oxidation number of oxygen in BaO2 is -1.

Read lesson note on Oxidation And Reduction (JAMB)

Read lesson note on Redox Reactions (WAEC)

Oxidation And Reduction

Redox Reactions

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Question 39 Report

If the volume of a given mass of a gas at 0ºc is \(29.5\text{cm}^3\). What will be the volume of the gas at 15ºc, given that the pressure remains constant.

31.6

62.2

32.7

31.1

Answer Details

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Kinetic Theory Of Matter And Gas Laws

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Question 40 Report

Which of the following constitutes a mixture? I. Petroleum II. Rubber latex III. Vulcanizer’s solution IV. Carbon (iv) sulphide

I, II and III

I, II and IV